The invention relates to a cover belt conveyor, in particular for steep conveyance of dusty material.
Cover belt conveyors are known, for instance, from German patent No. 936,918. In that case the closure strips are relatively flat sectional strips formed integral with a conveyor belt and provided with undercut zones in cross section which are arranged to differ in pairs and at which zones the strips enter into mutual engagement in closed condition, i.e. when passing through the conveyor path. At the locations where the cover belt is returned, the sectional strips of the cover belt are bent open and, at the same time, deformed considerably so as to release the sectional strips from the carrier belt. Due to the relatively great elastic deformation which the sectional strips experience for opening and closing of the longitudinal marginal closure, the conveyor belts of this known cover belt conveyor are subject to heavy wear. Furthermore, the configuration of the closure strips of this known cover belt conveyor provokes additional wear during the unavoidable relative movements in longitudinal direction of the conveyor belt. On the other hand, the conveyor space available is very small with this known cover belt conveyor because of the low height of the sectional closure strips. Cover belt conveyors of this type are not widely used.
German Offenlegungsschrift No. 25 19 447 discloses a cover belt conveyor having two conveyor belts which are provided with corrugated edges of the same height, positioned parallel to each other in pairs at the longitudinal margins and, if desired, having such a height that they define a very large conveyor space together with the conveyor belts. The conveyor space of this known cover belt conveyor also is sealed satisfactorily because the head of each corrugated edge touches the respective other conveyor belt, by virtue of which the conveyor space is sealed at both sides in the manner of a labyrinth packing. However, the seal tightness is maintained only as long as both conveyor belts each remain in contact with the corrugated edges of the other conveyor belt. The centrifugal forces generated in curved conveyor paths or possible inclusions of very coarse material may cause preliminary lift off of the conveyor belts from each other, unless relatively expensive contact pressure rollers are provided.